Cortisone is a hormone which increases in response to stress. Patients with pituitary problems are at risk to loose cortisol from day-to-day living and stress. Two tests are available and currently in use to measure the cortisone response, i.e. insulin tolerance test (ITT) and metyrapone tests. ITT, which produces low blood sugar and stimulates cortisol response is the gold standard test but needs more blood drawn and has more risks. Metyrapone is the other test which produces ACTH response by artificially blocking the production of cortisol. This test has less risk and needs less blood drawn. The two tests have not been compared simultaneously. The purpose of this study is to compare the two tests in each patient. The investigators will perform two tests in each patient to see if the metyrapone test has equal efficacy, sensitivity and specificity as the ITT.